The present invention relates to a hydraulic block for a hydraulic unit of a brake control system of a hydraulic automotive braking system.
A brake control system regulates wheel brake pressures and thus wheel braking forces of hydraulic wheel brakes of a hydraulic automotive braking system. Antilock braking systems, traction control systems and electronic stability programs, whose respective abbreviations are ABS, ASR and ESP, are possible, for example. The hydraulic block is provided for an automotive power braking system in particular.
Such hydraulic blocks are typically cubical metal blocks, usually made of aluminum or an aluminum alloy. These blocks are rectangular, approximately square, and have an approximate height of ¼-⅓ of a width or length. The hydraulic blocks have cylindrical, stepped-diameter blind holes as receptacles for hydraulic components of the brake control, connected by bores in the hydraulic block as lines, i.e., interconnected hydraulically and connectable to a main brake cylinder and to wheel brakes. Hydraulic components of brake controls of hydraulic automotive braking systems include, for example, solenoid valves, check valves, throttles, hydraulic accumulators, dampers and hydraulic pumps, which are installed in receptacles in the hydraulic block, usually being pressed into place and sealed in the receptacles by circumferential caulking to be fluid-tight and pressure-resistant.
Such a hydraulic block is described in International Patent Application WO 2012/150 120 A1. The conventional hydraulic block has the special feature of the main brake cylinder being integrated into it, i.e., the conventional hydraulic block has a main brake cylinder bore to receive two pistons of a dual-circuit main brake cylinder. The International Patent Application also describes a sensor for one stroke of the two main brake cylinder pistons as such without any specifications about the type and arrangement of the sensor.
German Patent Application No. DE 10 2008 020 934 A1 describes a dual-circuit main brake cylinder, whose rod piston protrudes out of the main brake cylinder, where it has a coupling flange. A rod situated in parallel with the main brake cylinder and displaceably held in a bore created parallel to the main brake cylinder bore in the main brake cylinder is in contact with the coupling flange. The rod has a permanent magnet inside the bore, which is also moved along with the rod piston. In addition to the bore for the rod, a position-detecting sensor, which detects a relative movement between the permanent magnet, which moves along with the rod piston, and the position-detecting sensor, and outputs a corresponding signal is mounted on the outside of the main brake cylinder next to the bore for the rod. A helical compression spring is provided as a restoring spring in the bore, forcing the rod against the coupling flange of the rod piston, so that the rod including the permanent magnet moves together with the rod piston. The rod piston is a main brake cylinder piston, which is mechanically connected by a pedal rod to a foot brake pedal.